This is FRESH AIR. I'm Terry Gross. Our guest Daniel Ellsberg became one of the best known opponents of the Vietnam War in 1971 when he leaked the Pentagon Papers, a secret Defense Department study of the war, to The New York Times and other publications. Ellsberg, then a national security analyst with top-secret clearances, was arrested and tried under the Espionage Act. A judge dismissed the charges when it emerged that officials in the Nixon administration had directed covert actions to discredit or silence Ellsberg, including tapping his phone and breaking into his psychiatrist's office, looking for compromising information.

Ellsberg is now 86, and he has a new book about his days before he studied the Vietnam War when he worked on American nuclear war strategies in the late 1950s and early '60s. Ellsberg was appalled by much of what he found and wishes he'd been able to leak those plans along with the Pentagon Papers. Daniel Ellsberg is the author of a 2003 memoir about the Pentagon Papers and Vietnam called "Secrets." He's also the subject of the Oscar-nominated documentary "The Most Dangerous Man in America." And he's a character in the forthcoming Spielberg film about the Pentagon Papers, "The Post." FRESH AIR's Dave Davies spoke to him about his new book, "The Doomsday Machine: Confessions Of A Nuclear War Planner."

DAVE DAVIES, BYLINE: Well, Daniel Ellsberg, welcome to FRESH AIR. You became famous for leaking the Pentagon Papers to The New York Times and other publications. And you tell us at the beginning of this book that you copied not just the Vietnam study but a lot of other material from your safe at the RAND Corporation about U.S. nuclear war plans. What were you going to do with that material?

DANIEL ELLSBERG: I planned to release that as soon as the Pentagon Papers, as they came to be known, had had whatever effect they could have on the Vietnam War. The nuclear information I thought then and now was actually more important. But the bombs were falling in Vietnam at that time, and I wanted to shorten that war as much as I could. So I planned to put out the nuclear documentation from my earlier work in the Pentagon and the RAND Corporation after my trial, actually. I expected a trial or perhaps several trials on the Pentagon Papers, as I did experience.

DAVIES: So you had all this material - hard copies. I mean, this wasn't a day when we had thumb drives. What did you do with that stuff?

ELLSBERG: I gave it to my brother to keep separately from the other because it might be a year or two or more before I put it out. And unfortunately he put it in a big box in a trash bag inside a trash dump to keep it away from the FBI who had been poking at his compost heap where he had earlier put it. So he put it underneath a big, iron stove on the - on a bluff in the trash dump in order to mark where it was.

Unfortunately, Tropical Storm Doria came about that very summer, 1971, and scattered the trash dump over the road, down the hill and all over the place. The stove itself was scattered for about a hundred yards. For the next year or two - actually about two years - my brother, with some help, tried to retrieve that box so that I could put it out. Meanwhile, I was on trial for the Pentagon Papers. And after trying with even a backhoe on one occasion to get a lot of garbage bags - green garbage bags but none with top-secret documents inside, he had to conclude that that was impossible. And that was a very great, very great disappointment for me for the next 40 years.

DAVIES: Right. And some of that material has since been declassified, which is part of what enables you to tell this story now. You went to work for the RAND Corporation, where you worked on high-level military strategy. Explain what the RAND Corporation was and what kind of work you did.

ELLSBERG: RAND, which stands for R and D - research and development - was really essence on research for the Air Force set up as a nonprofit corporation to do long-range research for the Air Force in the national interest. And in particular, when I came there in 1958 for the summer and then later permanently in 1959, our obsession really was trying to plant in our strategic forces in such a way that they couldn't be destroyed in a first strike by the Soviet Union. Those were the years that we all believed at RAND and in the Air Force that there was a missile gap in favor of the Russians and that a Russian surprise attack was a real possibility. And the idea was to assure retaliation for that so as to deter it so that no war would occur.

DAVIES: You know, this wasn't just a job for you, was it? I mean, it was kind of a special place to be. And it wasn't just a 9-to-5 paycheck thing for you, was it?

ELLSBERG: Not at all - I was working in the summer, especially when I arrived to get up to speed, probably 70-hour weeks there, reading top-secret or secret material - most of it was secret actually at RAND - and working on trying to avoid a nuclear attack by the Soviet Union. So nothing in the world seemed as important. In effect, we thought we were trying to save the world although we weren't very confident we'd be able to do it.

DAVIES: So you focused in your research and in your work at RAND on decision making in circumstances where information is incomplete or ambiguous. And you wanted to study how commanders in the military at all levels, right down to pilots, would make decisions on whether to attack Soviet targets in certain circumstances. And the research is fascinating as you describe it. What kind of access did you as the civilian have to military personnel?

ELLSBERG: Well, as a civilian consultant to the Commander in Chief Pacific Admiral Harry D. Felt at that time, I was doing a study for Office of Naval Research. I was loaned by the RAND Corporation to them - and looking at the actual reaction that could be expected at various levels to various execute messages, messages to go or - there weren't messages to not go, actually. There was no stop message. That's a little footnote here. But once a go message was received at any level, there was no provision whatever for stopping that or rescinding it or bringing it back...

DAVIES: Yeah, I...

ELLSBERG: ...If it was a mistake or if the president changed his mind or if there was - or if there was an end to the war, potentially.

DAVIES: Yeah. Let me just - if I can just cut in here...

ELLSBERG: Yeah.

DAVIES: ...Daniel Ellsberg - I mean, this is one of the jaw-dropping things as we read the book. If there was a launch, there was literally no way to recall a bomber. You can't recall missiles. But you know, things that had pilots - jet fighters and bombers - there was no way to send them - to bring them back.

ELLSBERG: Once they'd gotten an authenticated message that they were to execute the war plans - but the startling thing that I discovered at every level was that the general image that people have then and to this day that a message with the right code could only come from the president himself was never true. That was always a myth. At least it was from the late '50s when President Eisenhower had delegated authority - his authority - to launch nuclear weapons to theater commanders like CINCPAC or CINCSAC, the Strategic Air Command, or Europe in case there was an outage of communications or Washington had been destroyed or even the president had been incapacitated, as President Eisenhower was a couple of times.

That's almost essential that there be delegation like that in a nuclear era. Otherwise, a decapitating attack, as they call it, an attack on the command and control system, would paralyze us. A single bomb on Washington would paralyze our retaliation. Well, that could never be allowed, and it never has been allowed.

DAVIES: So not just the president but theater commanders have the authority under some circumstances to launch a nuclear attack. And these are experienced, high-level commanders. But what you found, I noted, when you looked in the Pacific is that these theater commanders had to be in communication with dozens and dozens of bases throughout the Pacific. And the question arises then, what about a base commander who has a number of fighter pilots or some aircraft - what - under what circumstances might they proceed on their own to launch an attack? What did you find?

ELLSBERG: Well, again, if they were out of communication with their superiors, a lot of them had authorization in the Pacific, I found, in the early '60s. And as far as I know, that continued. And I have to say, I don't know if it's true today, and we ought to find out. But actually, there were people even at a lower - as at a single base - you probably read an anecdote I had about Kunsan in Korea - in South Korea, the base possibly closer to communist territory of any of our bases in the world.

And the commander there clearly believed that he had the authority simply as a base commander to send his planes off if he thought they were endangered. So at that point, had there been what he thought was an attack - for example, an accident on some other base that he heard about or a crisis that was going on - he felt - he told me that he would send his planes off.

DAVIES: Wow. And this is - this was the guy...

ELLSBERG: That is...

DAVIES: ...Who questioned your authority to ask him these questions. And when finally he got it, he said, yeah, I - if it comes to it, that's my plan.

ELLSBERG: Well, I - he asked me, you know what they do if they - if I send them off to protect them. They weren't supposed to go to target at that point. They were supposed to rendezvous and to circle around for a while.

DAVIES: His pilots, yeah.

ELLSBERG: If they got no positive message to go ahead, they were to come back. And I asked him, what do you think they would do if that occurred? The first time they'd ever been sent to that rendezvous area in a serious false alarm and they didn't hear a message to come back - what would they do knowing, by the way, that the base might have been hit and that's why they weren't hearing any messages? And he said, well, I think they'd come back, most of them. And while I was reeling from that answer, he went on. Of course if one of them went ahead, they might as well all go, you know, because war would be on.

DAVIES: You know, what you discovered here I guess is something that happens often in military, you know, units where they expect to have to take initiative from time to time. And of course the stakes are enormously high with nuclear weapons. What were some circumstances that might lead to unwarranted, if you will, attacks on the Soviet Union - false alarms or explosions or natural phenomena?

ELLSBERG: Well, an incident that only became revealed many years after the Cuban missile crisis, in which I participated in 1962 - and I researched it really ever since. But it was decades before it became known that Khrushchev had in fact done something we thought no centralized communist commander would ever do or head of state. He had delegated and the Presidium, Politburo had delegated before President Kennedy's speech on October 22 announcing the blockade - they had delegated authority to local commanders to use their nuclear weapons.

Moreover, their submarines had nuclear torpedoes aboard which we didn't know. Now, one of those actually under what they thought was a depth bomb attack on the most critical day of the crisis, October 27 - they thought they were being attacked and were going to go down. And two - the commander and his second in command both needed - their decision was both needed. Both decided to fire a nuclear torpedo at the destroyers and the carriers that were harassing them.

DAVIES: The American destroyers, yeah, yeah.

ELLSBERG: Yeah. There happened to be - there was a carrier there in the vicinity, and we didn't even know there was a nuclear torpedo on those submarines. I would like to think we would not have been dropping mock depth charges on them to force them to the surface. But in any case, had a destroyer or a carrier blown up in the midst of the Caribbean, it would almost surely have been assumed at every level of our command that that had come from Cuba and that the time had come, as President Kennedy said in his speech on the 22, for an all-out attack on the Soviet Union. And that might not have waited for a presidential decision. It was one man who prevented that.

There was a commodore on that particular sub who was of the same military rank as the captain who had decided to shoot the torpedo, but as commodore, he did outrank him. And his position was - his decision was needed, too, and he decided not to do that. I think if he had decided otherwise or if he'd been on a different submarine not under attack at that moment, we wouldn't be here.

DAVIES: I want to take a break here, but let me reintroduce you. We're speaking with Daniel Ellsberg. He - you may remember that he leaked the Pentagon Papers back in the 1970s. His new book is "The Doomsday Machine: Confessions Of A Nuclear War Planner." We'll continue our conversation in just a moment. This is FRESH AIR.

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DAVIES: This is FRESH AIR, and we're speaking with Daniel Ellsberg. You may remember him as the person who gave the Pentagon Papers to The New York Times and other publications. He has a new book about his days as a nuclear war planner. It is called "The Doomsday Machine."

There is a remarkable chapter in your book called Questions For The Joint Chiefs. When you write that President Kennedy coming into the White House - he did not have nor did anyone on his team have a copy of essentially our plan for nuclear war, the Joint Strategic Capabilities Plan, and that when they asked for it, they were - you know, that the military was sort of reluctant and then they gave a briefing but not the actual plan itself, you had a copy. You examined it, and you wrote some questions. You - what troubled you about the plan that you saw?

ELLSBERG: Well, many things. It was a very strange plan. I'm not the only one who's called it the worst plan in human history. This was the plan for general war. It was an all-out attack on every city in the Soviet Union and China and attacks in effect in most of the Eastern Bloc because of air defenses and command and control that kept for no reserves, created fallout that would kill perhaps a hundred million people in West Europe for our own weapons if the wind were in the right direction for that.

And many - and a hundred million in other contiguous areas the Soviet Union like - neutrals like Austria and Finland and Afghanistan (laughter) actually but also several hundred million in the USSR and China - several hundred million killed. That added up to an intention in a U.S. first strike, if we preempted or if we escalated a war in Europe, to 600 million dead that they were calculating, a hundred Holocausts.

DAVIES: You know, when you were looking at nuclear policy in the 1960s, there were consequences of a widespread nuclear change that scientists weren't yet then aware of, what people call nuclear winter. You want to explain what that is and what stakes it presents?

ELLSBERG: Yes. What I discovered - to my horror, I have to say - is that the Joint Chiefs of Staff contemplated causing with our own first strike 600 million deaths, including 100 million in our own allies. Now, that was an underestimate even then because they weren't including fire, which they found was too incalculable in its effects. And of course, fire is the greatest casualty-producing effect of thermonuclear weapons. So the real effect would've been over a billion - not 600 million - about a third of the Earth's population then at that time.

What turned out to be the case 20 years later in 1983 and confirmed in the last 10 years very thoroughly by climate scientists and environmental scientists is that that high ceiling of a billion or so was wrong. Firing weapons over the cities, even if you call them military targets, would cause firestorms in those cities like the one in Tokyo in March of 1945, which would loft into the stratosphere many millions of tons of soot and black smoke from the burning cities.

It wouldn't be rained out in the stratosphere. It would go around the globe very quickly and reduce sunlight by as much as 70 percent, causing temperatures like that of the Little Ice Age, killing harvests worldwide and starving to death nearly everyone on earth. It probably wouldn't cause extinction. We're so adaptable. Maybe 1 percent of our current population of 7.4 billion could survive, but 98 or 99 percent would not.

DAVIES: You know, you did a lot of the strategic thinking about decision-making in - when you were in your 20s and 30s. And we haven't talked much about, you know, your personal life. But I know that when you were, I guess, 15, there was a terrible car accident where your family was driving. Your father fell asleep at the wheel, and your mom and sister were killed. And I'm sure that had very profound effect on - effects on you. But in this context, I'm wondering if it affected the way you think about risk and judgment.

ELLSBERG: It certainly made me aware that one's life could be changed in a terrible way very suddenly - in other words, that a - not just a tragedy, but a catastrophe was possible - in a way that many people have not experienced in their own lives. As I think about that when you ask the question, it occurs to me to say something that I think I've never - I don't remember ever saying before - thinking before. When my father set out on the Fourth of July on a flat, straight road in Iowa to reach our relatives in Denver on the Fourth of July - a very hot day with very little sleep the night before - it was not certain that he would fall asleep, and go off the road and kill the rest of my family, at that point.

It just was an intolerable risk that he was taking, and that's what I see happening in the world today. It's not certain that there will be - certainly, that there will war in North Korea, I would hope. That - there's still time to avoid that. It's not certain - you could say it's not even highly likely in any given year that these doomsday machines will actually be triggered. And yet, the image in my mind is, we are on the Titanic, racing at full speed on a dark night through iceberg-filled waters.

GROSS: We're listening to the interview FRESH AIR's Dave Davies recorded with Daniel Ellsberg, whose new book is called "The Doomsday Machine: Confessions Of A Nuclear War Planner." Ellsberg will talk about leaking the Pentagon Papers after a break. And we'll have reviews of the new Amazon series "The Marvelous Mrs. Maisel," and a new book about Ezra Pound, his poetry, politics and madness. This is FRESH AIR.

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GROSS: This is FRESH AIR. I'm Terry Gross. Let's get back to the interview FRESH AIR's Dave Davies recorded with Daniel Ellsberg, who's portrayed in Spielberg's new movie "The Post," about the Pentagon Papers and the Washington Post. Ellsberg leaked the papers. He was a high-level national security analyst in the '50s and '60s. His new memoir, "The Doomsday Machine," is about his days as a nuclear war planner and the war planning documents he wishes he'd managed to released to the public decades ago.

DAVIES: You're best known, of course, for leaking the Pentagon Papers, the secret Defense Department study of the Vietnam War. And you had spent many years for the government in Vietnam examining the war, concluding that it was futile, that there was no way to win it. And, you know, you had spent many years as a young man as a real patriot. I mean, you truly believed in the country. You believed in the security clearances, right?

ELLSBERG: Pardon me. I think I'm going to make it clear, but I wouldn't even want the question to raise that question in a way. I am a patriot, and that has never changed.

DAVIES: I understand, and forgive me for putting it that way. I mean, you are devoted to doing the right thing for your country. But at that time, you were - you respected all of the high-level security clearances that you had. And it must have been hard for you to take the step of taking this top-secret document and making it public. What did it take to get you to make that step?

ELLSBERG: Without young men going to prison for nonviolent protest against the draft, men that I met on their way to prison, no Pentagon Papers. It wouldn't have occurred to me simply to do something that would put myself in prison for the rest of my life as I assumed that would do. And if the Pentagon Papers somehow did not result in putting me in prison forever, the later trials I foresaw that are now revealed in this book for revealing nuclear secrets, what I was - I was certain would put me in prison for life. So obviously, that was not an obvious decision to make, except once I'd seen the example of people like Randy Kehler and Bob Eaton and others and David Harris who did go to prison to say that this war was wrong, the Vietnam War was wrong, and that they refused to participate in it.

DAVIES: How hard was it to actually copy the material?

ELLSBERG: Well, in those days, it was one page at a time. We didn't have these zip, zip, multi-page collators and whatnot machines that they have now or the - of course, the digital capability. So it took me a long time - months actually - to copy them, especially because, as I reveal in the book, I wasn't copying only the 7,000 top-secret pages of the Pentagon Papers - several copies of that. I was also copying more than that probably of my notes on nuclear war planning. And I've, of course, regretted for 40 years that a hurricane prevented me from putting those out.

DAVIES: So you would stay at night in the office copying and then come back to work during the day.

ELLSBERG: Yes.

DAVIES: Did you - did night watchmen ever come upon you or anything?

ELLSBERG: Well, twice in that office, which was a small advertising office owned by a friend of a friend really. Twice during that period, police came to the door because she had turned the key the wrong way and set off the burglar alarm. And on one of those occasions, my children were there. That was the one time. And my - police came in and found my son running the Xerox machine.

DAVIES: (Laughter).

ELLSBERG: No. I think I was running the Xerox machine and he was collating or might have been the other way around. He was then 13 and my daughter, who was 10, was cutting off top secret from the tops and bottom of the pages with the scissors. The reason they were there was that I expected to be in prison very shortly. I'd hoped to get the papers out quickly, and that didn't happen in the Senate.

But I wanted them to know that their father was doing something in a businesslike way, a calm, sober way, that I thought had to be done. And I did let my older son know in particular that it might - in fact, would probably result in my going to prison. And that was an example that I actually wanted to pass on to my children that they might be in such a situation.

DAVIES: So it was very clear that Nixon regarded you as a really dangerous man because, you know, he had information - you'd leaked these secrets and there was information about his own internal thinking about Vietnam. And it was the actions of, you know, operatives of the Nixon administration that led to the dismissal of charges at your trial because we learned that they in fact - they planned a break-in at your psychoanalyst's office and some other things, too, right? What else did they do?

ELLSBERG: Well, Bernard Barker - Macho Bernard Barker of the Bay of Pigs, a CIA asset - said that his mission was to break both my legs, but I don't think that would have shut me up totally in the hospital bed. I think they probably wanted something to happen to my jaw, but they were going to attack me in the course of a rally that I was speaking to on the steps of the Capitol on May 3, 1972. And they brought 12 of these CIA assets, mostly Bay of Pigs veterans, up and was shown my picture and said I was to be incapacitated totally.

And when their prosecutor, William Merrill told me this later, I said, well, what does that mean - kill me? He said the words were to incapacitate you totally, but you have to understand these guys never use the word kill. Use neutralize, all right, terminate with extreme prejudice. They use a lot of euphemisms, CIA people, for assassination.

DAVIES: You know, you - your trial ended when the government actions taken against you were exposed and there was a - the charges were dropped. You took action to disclose government secrets then that you felt the American public needed to know. And I'm wondering what your attitude is today towards classified information and how you regard the actions of, you know, Chelsea Manning, say, and Edward Snowden.

ELLSBERG: I identify more with Chelsea Manning and with Edward Snowden than with any other people on Earth. They're - we all come from very different backgrounds, different ages, different personalities, but we all faced the same question, which is who will put this information out if I don't? And each of us came to the conclusion that this information that the public had to know would have to be put out by us, by ourselves, because no one else was going to do it. Edward Snowden, for instance, had hoped that Barack Obama would carry out his promise to make a transparent government and not hold on to secrets that shouldn't be secret at that point, and he was disappointed actually.

There were nine prosecutions for leaks - three times as many as all previous presidents before. I was the first of those, actually, ever to be prosecuted. There were two more before Obama and then nine under Obama. And that's what led Snowden finally who's - had to decide it was up to him to do it. And I think that was the right thing to do, and I really admire him. As I said, they're - I regard him as a friend. I have met him in Moscow. I made a special trip for that and - but also a hero of mine. And the same is true of Chelsea Manning, whom I haven't yet had the opportunity to meet.

DAVIES: Tell me about meeting Edward Snowden. I imagine he was excited to meet you.

ELLSBERG: Well, I think he identifies with me on the same grounds. You know, I said earlier, without draft resisters like Randy Kehler or Bob Eaton, no Pentagon Papers. Well, I was very gratified to have Edward Snowden say on a Skype meeting - a couple of times actually - say that without Daniel Ellsberg, no Ed Snowden. That was very nice to hear because I'd never gotten feedback like that. I'd been urging people to use their judgment and their conscience for decades at that point and it just hadn't happened - to put out information that the public needed to know, and it just hadn't happened.

For example, in the Iraq War, I think that if there had been an Edward Snowden or - and now that I've met him - at a higher level with greater access than he had - or a Chelsea Manning with greater access than she had at her low level, in the 2002 there would have been no Iraq War, no ISIS, no - nothing that we've seen later. That was a mad venture based on terribly unreal - totally unrealistic beliefs.

And I think that if the information had been put out, Congress would not have gone along with that war as they did - just as I'm very sorry to say if I'd put out the information in my safe in the Pentagon about our widening war that was projected in 1964, Senator Wayne Morse, one of the two senators who voted against that widening - the Tonkin Gulf Resolution - told me if you'd put that out, there would have been no vote in the committee. It would have not passed the committee. And if they bypassed that to go to the floor of Congress, it would not have passed.

So he's telling me that I had had the power to avert the Vietnam War. I think that's true, not only of me. That's a heavy burden to bear. I share it with a thousand others who had that kind of access. You know, when I said that Roger Morris had - did have the access to the nuclear target folders in 1969 and Nixon feared that I had those from Morris, I didn't because he didn't put them out. And later, Roger told me that was the failure of which he is most ashamed and that he most regrets in his life. He said to me we should have thrown open the safes and screamed bloody murder because that's exactly what it was.

DAVIES: So many of us love the film "Dr. Strangelove," the Stanley Kubrick film about, you know, the nuclear confrontation that's started by a rogue American commander, and it spirals off from there. You know, to us, it was a great, dark comedy. I'm wondering what you thought when you saw it. And you were doing nuclear war planning then.

ELLSBERG: When I was working for the Defense Department now in 1964 as a full-time employee, it was part of our job, we thought, for my boss and I, Harry Rowen, deputy - assistant secretary of defense - during the day to go see this new film, "Dr. Strangelove," see what it looked like. And when we came out into the daylight that afternoon, we each agreed that's a documentary.

DAVIES: Daniel Ellsberg, thank you so much for speaking with us.

ELLSBERG: This was a pleasure - very good questions. Thank you.

GROSS: Daniel Ellsberg's new book is called "The Doomsday Machine: Confessions Of A Nuclear War Planner." He spoke with FRESH AIR's Dave Davies, who's also WHYY's senior reporter. After our break, Maureen Corrigan will review the new book "The Bughouse: The Poetry, Politics, And Madness Of Ezra Pound." This is FRESH AIR.